Turbocharged and supercharged engines may be configured to compress ambient air entering the engine in order to increase power. Because compression of the air may cause an increase in air temperature, a charge air cooler may be utilized upstream of the engine air inlet to cool the heated air before it enters the engine, thereby increasing air density and improving combustion of fuel by an engine cylinder, resulting in more power and improved fuel economy. However, the cooled air exiting a charge air cooler upstream of an engine may be re-heated by the engine, particularly during high engine load and/or high engine temperature conditions, thus negating many of the benefits of the charge air cooler.
Other attempts to address cooling intake air include a cooling duct surrounding an air intake line. One example approach is shown by Johnson in U.S. Pat. No. 7,658,183. Therein, latent heat from the intake air is removed via a chilled intake air assembly duct located upstream of the engine.
However, the inventors herein have recognized potential issues with such systems. As one example, by placing the chilled intake air assembly duct relatively far from the engine, the intake air may still be re-heated prior to entry in the cylinders.
In one example, the issues described above may be addressed by a system comprising a cylinder head defining a plurality of cylinders, the cylinder head including a plurality of inlet ports each fluidically coupled to a respective cylinder, a refrigerant supply, and a refrigerant passage surrounding each inlet port and fluidically coupled to the refrigerant supply, the refrigerant passage shaped to correspond to an outer profile of each inlet port. In this way, intake air may be re-cooled at the inlet ports prior to entering the cylinders for combustion, thus increasing available engine power and reducing emissions.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.